Rising Temperatures Are Scrambling the Base of the Ocean Food Web

Humans are living in a plankton world. These minuscule organisms are spread across the oceans, covering nearly three-quarters of the planet, and are among the most abundant forms of life on Earth.

But a warming world is throwing plankton into disarray and threatening the entire marine food chain that is built on them.

A year ago, NASA launched a satellite that provided the most detailed view yet of the diversity and distribution of phytoplankton. Its insights should help scientists understand the changing dynamics of life in the ocean.

“Do you like breathing? Do you like eating? If your answer is yes for either of them, then you care about phytoplankton,” said Jeremy Werdell, the lead scientist for the satellite program, called PACE, which stands for “Plankton, Aerosol, Cloud, ocean Ecosystem.”

Historically, research from ships has captured limited snapshots in time, offering only glimpses of the ever-changing oceans. The advent of satellites gave a fuller picture, but one still limited, like looking through glasses with a green filter.

“You know it’s a garden, you know it’s pretty, you know it’s plants, but you don’t know which plants,” explained Ivona Cetinic, a NASA oceanographer. The PACE satellite effectively removes the filter and finally reveals all the colors of the garden, she said. “It’s like seeing all the flowers of the ocean.”

These flowers are phytoplankton, tiny aquatic algae and bacteria that photosynthesize to live directly off energy from the sun. They are eaten by zooplankton, the smallest animals of the ocean, which, in turn, feed fish and larger creatures.